I wouldn't do it, but I see others do it once in awhile. Many a player has stated that a good Break Cue has a shaft, with a stiff spine. A small diameter shaft doesn't have a spine. A Thin shaft has a smaller tennon in the ferrule, so it can be damaged.
A good Break Cue is about $300.00. That isn't much to spend on a cue that will last you the rest of your life...
NOTE; The Break Shot is "The LINK" between games. Give this shot some real consideration in your practice & in your purchase of equipment. You'll be glad you did.